Re: How to use [NSURL loadResourceDataNotifyingClient:usingCache:] ?

[Richard Frith-Macdonald]

On Monday, March 24, 2003, at 09:54  pm, Yen-Ju Chen wrote:

> Hi,
>
>  I try to use [NSURL loadResourceDataNotifyingClient:usingCahce:],
>  but it doesn't work at all.
>  I implement both -URLHandleResourceDidBeginLoading:
>  and -URLResourceDidBeginLoading: in the client.
>  But they are never called.
>  Does it work in GNUstep ? Or am I doing something wrong ?

You are doing something wrong ...

1. The -URLHandleResourceDidBeginLoading: method is sent to the NSURL 
object, not to its client.  So implementing this in the client will 
have no effect.  If you want the method to be called you need to make 
your object a client of an NSURLHandle rather than an NSURL.

2. The -URLResourceDidBeginLoading: method is not part of the URLClient 
protocol, so NSURL clients should not and do not get sent a method 
notifying them when loading starts.  This is presumably because the 
only way to make an object a client of an NSURL is by sending the NSURL 
instance a -loadReasourceDataNotifyingClient:usingCache: method.  ie 
your code already knows that loading has just begun, so it can tell the 
client that itsself.  I can't think of any other reason why Apple would 
have decided not to put a method like that in the protocol.